Annual report pursuant to Section 13 and 15(d)

EMPLOYEE BENEFIT PLANS (Details)

v3.19.1
EMPLOYEE BENEFIT PLANS (Details)
12 Months Ended
Dec. 31, 2018
USD ($)
item
Dec. 31, 2017
USD ($)
Defined Contribution Plan    
Defined Contribution Plan 401(k) | $ $ 600,000 $ 700,000
Multiemployer Pension Plans    
Number of multiemployer pension plans | item 55  
Maximum amount of lump sum distributions when fund is in critical state | $ $ 5,000  
Minimum    
Multiemployer Pension Plans    
Number of union multiemployer pension plans | item 150